In recent years, the capacities of the flash memories have been increased, and adaptors removably attached to various types of memory cards, memory packs incorporating one or more memory cards and other information processing devices mounted with memories have been developed.
There have been known various structures of the memory packs for incorporating a memory card such as a PC card. Further, inventions have been made to meet a demand for reduction of the thickness of the PC card.
In general, terminals of the memory card are connected to an electric circuit provided in the memory pack via a connector. For example, an IC card connector having the smallest possible thickness yet having a sufficient mechanical strength is known (see, for example, JP 2002-329553A). The IC card connector is adapted to receive an SD card as the IC card inserted therein with terminals of the SD card facing up, and includes a plurality of connection terminals embedded in a base thereof to be brought into contact with electrode pads of the terminals of the SD card.
Further, a PC card including a plurality of memory cards is known (see, for example, JP 9-102019A).
FIGS. 10 to 13 illustrate an example of a prior art memory pack of a PC card size. FIG. 10 is a perspective view of the memory pack with its upper cover removed, and FIG. 11 is a perspective view of a printed board and a connector. FIG. 12 is an explanatory diagram for assembling, and FIG. 13 is a sectional view taken along a line X-X in FIG. 10.
In FIGS. 10 to 13, a reference numeral 100 denotes a frame having a bottom and a housing space. A reference numeral 101 denotes an upper cover of a thin rectangular metal plate which is combined with the frame 100 to define a housing. In general, the upper cover 101 is fixed to the frame 100 by a snap-in or fusion bonding method or with the use of screws. A reference numeral 102 denotes a printed board, which is fixed in the housing space of the frame 100 with the use of an adhesive or screws. An electronic component 108 such as a control LSI is mounted on a rear surface of the printed board 102. A reference numeral 103 denotes a pair of connector bases, which are composed of an insulator such as a resin and disposed in a middle portion of the printed board 102 as extending widthwise of the printed board in parallel relation. The bases 103 each have a plurality of recesses extending widthwise thereof and arranged at predetermined intervals in parallel relation. A reference numeral 104 denotes contacts, which are composed of gold-plated phosphor bronze or beryllium copper and fitted in the recesses of the bases 103 at a predetermined pitch in parallel relation. One-end portions of the contacts 104 project from the corresponding bases 103 to overhang the printed board 102. The other ends of the contacts 104 are electrically connected to a circuit pattern (not shown) formed on the printed board 102 to form a predetermined electric circuit. The connector is constituted by the bases 103 and the contacts 104.
A reference numeral 105 denotes memory cards. In this example, four SD memory cards are used, and accommodated in the housing of the PC card. A reference character 105a denotes a plurality of recesses formed in an edge portion of each of the memory cards 105 and arranged at the same pitch as the contacts 104. Terminals 105b are respectively provided on bottom surfaces of the recesses 105a, and brought into contact with the contacts 104 for electrical connection. A reference numeral 106 denotes a card connector, which is mounted on the printed board 102 and permits signal transmission with respect to an external device. A reference numeral 107 denotes a ground plate, which covers the card connector 106 for reduction of influences of noise.
When the memory pack is assembled, the connector with the plurality of contacts 104 preliminarily attached to the bases 103 thereof is fixed to the printed board 102 as shown in FIG. 11. Then, as shown in FIG. 12, two front memory cards 105 are inserted in an arrow direction A and the other two memory cards 105 are inserted in an arrow direction B toward the bases 103 of the connector. With terminal-side edges of the memory cards 105 abutting against walls of the, bases 103, the contacts 104 are in contact with the terminals 105b of the memory cards. As shown in FIG. 10, the resulting unit is fixed in the frame 100, and the upper cover 101 is attached to the frame 100.
In the prior art, however, the contacts 104 project from the bases 103 in an uncovered state as shown in FIG. 11. Therefore, when the connector is transported or attached to the board 102 or the memory cards 105 are inserted into the connector, the contacts 104 of the connector are liable to be deformed in contact with various things. This may result in insufficient contact between the contacts 104 and the terminals 105b of the memory cards 105.